1) I can not image a customer complaining because their TV is not showing HD. I can understand HD on larger TVs but the smaller ones not sure people are going to pay that much attention to the detail. Most sports bars I've been too your lucky to have all the TVs working properly. But over all do you have the budget for having HD signal available on all TVs. Your talking 5 cables vs 1.
2) Both ends of the cable need an RCA connection (approximatey ~$2 a piece) depends on the vender and type. Silver connectors are fine, I would pay extra to get gold. Check out www.libertycable.com
I believe you might need to be a dealer though to buy.
3) If you want every tv to have whatever satellite you want to watch then you you will need several matrix switchers. Here is an example of 2:http://www.video-storm.com/proddetail.asp?prod=CRM88http://www.neoprointegrator.com/imperial.php
The first one can do upto 16 component video signals in (satellites) and 16 component outs (TVs) with 14 digital audio in (satellites) and 14 digital auio outs (TVs). Not sure why audio isn't 16.
The second has 8 component inputs (satellites) and 16 component outputs (TV). You can stack units to have upto 48. You would need additional ones to do analog audio (2 RCAS) or digital audio (1 RCA).
Figure atleast $2000 per match switch so talking upto $10000 depending on how many matrix switches you need and the price of each.